Year	% of cohort
1971	94.5448379516602
1972	91.0961685180664
1973	92.395149230957
1974	93.9861068725586
1975	93.834228515625
1976	92.1361770629883
1977	95.204460144043
1978	95.9070816040039
1979	97.2515029907227
1981	93.9861297607422
1982	96.8624877929688
1983	96.8574676513672
1984	98.8652420043945
1985	99.3473663330078
1986	99.2788772583008
1987	99.3266525268555
1988	99.3684997558594
1989	99.4376831054688
1990	99.8547210693359
1991	99.4954299926758
1992	99.5080184936523
1993	99.4252471923828
1994	99.275520324707
1997	96.8527908325195
1998	99.0380783081055
1999	99.0654602050781
2000	98.8968811035156
2001	98.4722671508789
2002	99.3654708862305
2003	97.4190521240234
2004	98.5435104370117
2005	98.8442687988281
2006	97.2355270385742
2007	98.5837173461914
2008	98.7311401367188
2009	99.3285369873047
2010	99.1040802001953
2011	99.2738418579102
2012	99.4779434204102
2013	99.3471832275391
2014	99.5964965820312
2015	99.3943328857422
2016	99.5034408569336
2017	99.2289581298828
2018	99.3061294555664
2019	99.1194763183594
2020	99.7165985107422
2021	98.7550430297852